/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.runtime.core.transformer.simple;

import org.mule.runtime.api.metadata.DataType;
import org.mule.runtime.core.api.transformer.TransformerException;
import org.mule.runtime.core.config.i18n.MessageFactory;
import org.mule.runtime.core.transformer.AbstractTransformer;

import java.nio.charset.Charset;
import java.util.Map;

/**
 * <code>MapLookup</code> looks up and returns an object from a Map based on a key.
 */

public class MapLookup extends AbstractTransformer {

  protected volatile Object key;

  public MapLookup() {
    registerSourceType(DataType.fromType(Map.class));
    setReturnDataType(DataType.OBJECT);
  }

  @Override
  public Object doTransform(Object src, Charset encoding) throws TransformerException {
    if (src instanceof Map) {
      if (key != null) {
        return ((Map) src).get(key);
      } else {
        throw new TransformerException(MessageFactory
            .createStaticMessage("Property 'key' must be set in order to use this transformer."));
      }
    } else {
      throw new TransformerException(MessageFactory.createStaticMessage("Message to transform must be of type java.util.Map"));
    }
  }

  public Object getKey() {
    return key;
  }

  public void setKey(Object key) {
    this.key = key;
  }

}
